Need gas

in the last week my jaguar xj sport when i try to fill the gas tank it keeps bubbling over and im only able to get about a gallo of gas in it. whats wrong?

Likely some sort of valve in the filler neck is stuck closed. Try poking it open with a stiff wire, or with plastic string from a weed trimmer.

Maybe there’s blockage in the line. Stick a stiff piece of plastic tubing (like Tygon) into the filler neck and see if it gets stuck on something.

Let’s assume this car has a charcoal cannister in the fuel vapor recovery system. If you habitually top off the tank after the gas station pump shuts off, you may have damaged the cannister, which will cause the problem you describe. Hope it’s something else…VERY expensive repair on a Jaguar.